Vertical cyclicaly operating flat sack machines of the type described above are known. A distinguishing feature is that the foils move in a common vertical foil plane, at least through the sealer and neighboring stations. The foil plane extends vertically and in a right angle with respect to the machine frame of the flat sack machine, i.e. the operator standing in front of the flat sack machine looks in the direction of the foil plane and on a mainly vertically extending side on the machine frame. The individual aggregates and stations are mounted on the front of the machine frame. The sealer of such flat sack machines has the well known purpose to bond together by pressure and temperature two foils facing each other with their inner sides, thereby creating the flat sacks. The inner sides of the foils are provided with a sealing mass, especialy polyethylene. Usually multiple use is applied, i.e. a plurality of sacks are simultaneously filled, sealed, and treated in parallel. The width of the foils is used so that there is little waste, i.e. the longitudinal sealing tools, which operate along the edges of the foils, are adjusted so close to the edges that unavoidable residue of the sealing mass, which is pressed out from between the two foils under pressure, build up on them. This sealing mass builds up on the outer longitudinal sealing jaws. Residue of the sealing mass may also collect on the outer flat sacks, especially when such residue has build up on the outer longitudinal sealing jaws and the residue is torn off the outer flat sack and carried along. This poses not only the danger that the outer flat sacks have edges that are not pretty. If there is a larger build up of sealing mass, this may come into contact with the paper outer layer of the foil, which leads to the danger of the sack tearing during the cyclic movement of the flat sacks. This in turn leads to an interruption of the production in order to remove the refuse. Considerable cleaning of the flat sack machine and its aggregates becomes necessary.
In order to counteract the disadvantages and dangers described above, there is the possibility in known flat sack machines (e. g. the machine LA-3 according to the pamphlet "Flat sack machines" by the applicant) to liberate the two symmetrically fashioned units of the sealer from a locked operating position and to manually pivot the units by 90.degree.. The pivoting takes place about vertical axes, so that the clamping plate with the sealing tools arranged thereupon moves relative to the two foils and the filling means. Since the filling means extend more or less into the sealer, and the longitudinal sealing tools are arranged parallel to the filling means, there is the danger the sealing tools touch the filling means, change their carefully adjusted relative position or even damage them during the manual pivoting of the units into the fitting and cleaning position. The danger of this happening is high because the longitudinal sealing tools and the filling means may overlap in a large region during the pivoting of the units about the vertical axes and therefore may touch during the pivoting. It should additionally be ascertained that the pivoting is done only from the separated position of the sealing tools. At the end of the interruption of the operation the units have to be pivoted back and locked into position manually. In the fitting and cleaning position the sealing tools may also be cleaned from adhering sealing mass, which is usually performed using a brush. When setting the flat sack machine to a different product or a different format the sealing tools have to be changed, which is also possible only in the fitting and cleaning position. The sealing tools are arranged vertically above each other also in the fitting and cleaning position, so that during the removal and fitting of the sealing tools it is necessary to support these in their respective positions. The change thus becomes elaborate and time consuming.
All the products being packaged are also subjected to the temperature of the sealer while in its vicinity. The sealing tools may have temperatures of up to 180.degree. C. Especially pharmaceutical and cosmetic products may be adversely affected by excessive heat, which can already be the case during a short interruption of the production process, when the units of the sealer are not manually pivoted into the fitting and cleaning position during such an interruption of the operation. Due to the other already described dangers, especially the damaging of the filling means, the elaborate manual pivoting into the fitting and cleaning position is sometimes not performed, though. Such an often recurring short interruption of the operation is for instance given during the changing of the rolls of foil. During interruptions of the operation, in which the pivoting of the units into the fitting and cleaning position is not performed, there is the further danger that the inner side of the foil adheres to the product guiding filling means. This leads to a tearing of the foil upon restarting the flat sack machine.
In the known flat sack machines it is naturally attempted to process foils as wide as possible, i.e. to simultaneously form a plurality of flat sacks in parallel. This necessitates that the sealing tools extend rearwards toward the machine frame relative to a vertical plane connecting the two vertical pivot axes, though. During the pivoting of the units the rear part of the sealing tools approaches the foil and the filling means due to the geometric circumstances, i.e. it comes closer to the foil and the filling means during this pivoting, so that the danger of bending, pushing, and changing the setting of the relative position of the filling means is especially great. This danger is the greater the larger the usable width is. This just described region of danger extends over the whole height of the sealing tools.
There are also vertically operating flat sack machines known, in which the arrangement is such that the plane of the foils is parallel to the casing wall of the machine frame, so that the operating personnel .standing in front of the flat sack machine looks upon the plane of the foils. The sealing tools are then arranged with their one unit in front of the plane of the foils and with their other unit behind the plane of the foils. The unit provided in front of the plane of the foils is then removable, in order to be able to perform fitting and cleaning procedures. The unit located behind the plane of the foils is only accessible by removing both foils, though, which necessitates an especially elaborate rethreading of the foils before the restarting of the machine.
From the U.S. Pat. No. 4,854,109 it is per se known for machines, which seal materials between two foils, to pivot away parts to be removed temporarily from the foil by pivoting these about horizontally projecting axes, which are mainly in the lower region of the parts to be pivoted. The sealing tools are not affected by this, though. They are arranged on a sled, with the aid of which they are translatable in a direction perpendicular to the plane of the foils.